DIY power box

[bigredball90]

Looking at trying to build my first powerbox for camping and backup power for a few things around the house if we loose power. Ive never built a battery pack or anything like this before so I could use some guidance. I want to charge it primarily from 110 from the house, and the van while driving. Ill be camping in a forest so solar wont work well. Id like to be able to "plug it in" to the van to run the fan and lights, and usb ports on it to charge misc stuff. I would really like to have the ability to use it as an emergency jump pack for the van if the engine battery dies. Ill probably add and led flood light or 2 on the box in case I need light somewhere outside. Couple of computer fans to keep the box cool. Whats the easiest way to control them? Temp sensor?

I need 75ah of usable power for a weekend trip. Ill be powering a roof fan, led lights, and charging misc things. Im looking at 100ah lifepo4 calb? for a batteries. Im open to battery options.

I saw somewhere someone used a large anderson connector to alligator clips for jump starting batteries if needed. How do I figure out the cable size for that? I think I can use an anderson connector to plug the box into the van for the lights and fan.
List of things I know I need: BMS, battery isolator, charge controller, 12v to 110v inverter, fuse box, 2 small fans for case.

Thats all I can think of for now, any help or insights would be great!

 

[Craig]

If you do not want to use solar you could do something simple like getting a progressive dynamics shore charger for rv's. this will convert AC into dc to charge your batteries. you could plug this in at home to charge batteries. While you are on the road you could hook up your inverter to cars system and plug progressive dynamic charger into inverter to charge batteries. then switch the inverter to your storage battery bank to power whatever you need with AC while camping.

you can also get a dc-dc converter to charge your storage battery from your car while its running and not have to switch things around.

the first way would require more effort from time to time but could save 1 device.

 

[bigredball90]

Thanks for the reply. I couldnt find the progressive dynamics controller but Ive found this one it looks like it could do both AC/DC and balance the battery. https://hobbyking.com/en_us/turnigy...276&indexName=hbk_live_magento_en_us_products
Would this work?
Would there be any advantages or disadvantages of using headway 38120 8ah cells over say 4 large prismatic cells?
Thanks

 

[Craig]

That Item looks like it could work but t seems a little small
this is waht I was refering to
https://www.ebay.com/itm/PROGRESSIV...:w5AAAOSwMo9a6Lly:sc:USPSPriority!95023!US!-1

please dont take my word for it others here may also help.

 

[Rider]

You could do something like I, and many others, have done, build a solar charger but don't add a solar charger or panels. A box with a 100Ah battery and properly sized inverter with a battery charger built in.

For Camping

I wanted a small power system for camping, so I used a lot of information gleaned from Will's YouTube vids to put together a system. My main objective was to provide enough power to run a fridge and keep it compact. The Solar Charger: As I was walking thru BJs, I spotted a tiered toolbox that...

diysolarforum.com

 

[Steve_S]

Any respectable Inverter/Charger combo unit can certainly handle 120VAC input as "shore power", be able to charge the battery bank and inverter DC to AC without a blink. Some can even disconnect from AC internally once batteries are full (not all but some like Samlex do but it's more $) . There are some good "Value" systems that do this as well albeit they are generally less efficient, running an average of 85-90% efficiency. WARNING, NOT All support LFP or are not programmable for settings, this is important ! Inverters that use dip switches and dial potentiometers to adjust do NOT support LFP, hey typically only handle Lead Acid Variants and those that have an LFP setting use a hobbled FLA profile, not always the wisest move.

BTW: LFP isn't the best to use for Jump Starting a vehicle, rarely once in a while (ie blue moon) may be ok but it isn't advisable, they simply are not made for that

 

[bigredball90]

Rider - yes thats my plan for now just AC or DC from the van. I guess I missed inverter/chargers any brands better than others? Probably wont need much, maybe 1k continuous. Would really only be for fans, lights, maybe a TV if we lose power. Its better for the cells if I dont charge to fast right? The pack would only be used once a month or so I dont mind a slower charge if its better for the pack.

Thanks for the warning, Ill be sure to check before I buy. I dont plan on using it to start a vehicle unless I have to. I usually wont have cell reception where I camp, so if for some reason my engine battery dies I might be able to start it with the powerpack.